photo-litho



UNITED STATES PATENT OFFICE.

W. LEWIS AND W. H. LEWIS, OF NEW YORK, N. Y.

APPARATUS FOR HOLDING DAGERREOTYPE-PLATES.

Specification of Letters Patent No. 6,819, dated October 23, 1849.

To all 'whom t may concern.'

Be it known that we, l/VILLIAM LEWIS and WILLIAM HENRY Lnwis, both ofthe city of New York, daguerreotype apparatus manufacturers, haveinvented and made and applied to use cert-ain new and usefulimprovements in the means of securing the plates used in daguerreotypeapparatus in place for the purpose of polishing them, such improvementsconsisting in so applying a horizontal vise to one end of the plate thatit shall be firmly held in place for that purpose by mechanical means,for which we seek Letters Patent of the United States, and that the saidimprovements are constructively, operatively, and substantially setforth and shown in the following description and in the drawing annexedto and making part of this specification of our said improvements, inwhich- Figure l is a plan, and Fig. 2 a side elevation of the apparatuscompleted, as in use; Fig. 3 is a sectional elevation, as through theline A, B, of Fig. l, showing the parts, as when not in use.

Like letters and numbers, as marks of reference, apply to the sameparts, in each of the several figures.

In these a is the met-al stock piece, shown as to be secured on a bench,or table, by screws 1, l, l, and prolonged and spread out, to form a bedplate t, which is shown in Fig. 3, as having a slot 2, through thecenter, the outer end of the slot is enlarged, to pass the head of thescrew 3, which passes into the under side of the changeable bearingplate c, this may be made larger than shown in the drawing, and coverthe whole of the bed plate b, when used for polishing a larger plate,the center slot 2, serving for more than one size of bearing plates 0,'the stock piece a, is formed with a groove, to receive the aw stockpiece, d, which, at the outer end, is formed as a rabbeted jaw, or chop,6, and on the side of the groove, two small standards 4, 4, receive,through them, a pin 5, that forms the fulcrum for a lever e, having acam head 8, seen best in Fig. 3; a screw 7 goes through the tail end ofthe jaw stock d, into a cup, in a solid part of the stock piece a, toadjust the j aw stock d, for use; and a small helical expansive spring,10, beneath the rabbeted jaw 6, lifts that the lever e, thrown in theopposite direction,

it will take the position, shown foreshortened in Fig. l ,i but when thelever e, is depressed in the same direction, it will assume the positionshown in Fig. 2, the cam 8, depressing the jaw stock d, spring 10, andchop 6, forces that down on the end of the plate 9, holding it firmly inplace, until the polishing is effected; when the lever is turned back,to the position shown in Fig. 3, and the plate 9 is removed, for othersto be successively put on, and held for polishing,.in the saine manner.

It will be seen, that if the screw 7, was placed between the standards4, 4, so as to operate downward on the jaw stock, and the cam S, withthe lever e, placed at the tail end of the jaw stock, either beneath it,or in a fork at the end, nearly the same result-s will be obtained, byhaving the cam larger, on account of acting with the increased length ofthe jaw stock; but we do not recommend any such change, as it is not soconvenient, in use, as when the cam is nearer the holding jaw 6, as wehave described and shown it. i

YWe do not claim to have invented a vise, for this or any similarpurpose; nor do we claim to have invented any of the parts, hereindescribed, as all are well known; but

TWe do claim as new, and of our own invention, and desire to secure byLetters Pat ent of the United' States-A The application of the cam 8,acting to depress the rabbeted chop 6, on the plate 9, beneath,conjointly with the screw 7, to adjust the parts7 for the purpose ofholding plates, while polishing Athe same, substantially as describedand shown.

In witness whereof, we have hereunto set our signatures, thistwenty-first day of July, in the year one thousand eight hundred andforty-eight.

WILLM. LEWIS. W. H. LEWIS. Witnesses:

WM. TERRELL, LEMUEL W. TERRELL.

